Reduced-distortion hybrid induction heating/welding assembly

ABSTRACT

In certain embodiments, inductive heating is added to a metal working process, such as a welding process, by an induction heating head. The induction heating head may be adapted specifically for this purpose, and may include one or more coils to direct and place the inductive energy, protective structures, and so forth. Productivity of a welding process may be improved by the application of heat from the induction heating head. The heating is in addition to heat from a welding arc, and may facilitate application of welding wire electrode materials into narrow grooves and gaps, as well as make the processes more amenable to the use of certain compositions of welding wire, shielding gasses, flux materials, and so forth. In addition, distortion and stresses are reduced by the application of the induction heating energy in addition to the welding arc source.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims priority from and the benefit of U.S.Provisional Patent Application Ser. No. 62/063,678, entitled “WELDINGDISTORTION REDUCTION UTILIZING INDUCTION HEATING,” filed Oct. 14, 2014,U.S. Provisional Patent Application Ser. No. 62/063,688, entitled“WELDING PRODUCTIVITY IMPROVEMENT UTILIZING INDUCTION HEATING,” filedOct. 14, 2014, and U.S. Provisional Patent Application Ser. No.62/063,698, entitled “METAL WORKING INDUCTION HEATING HEADCONFIGURATIONS,” filed Oct. 14, 2014, each of which is herebyincorporated by reference in its entirety for all purposes.

BACKGROUND

The present disclosure relates generally to the field of welding systemsand processes, and more particularly to welding systems and processesthat utilize induction heating as an additional source of heatingenergy.

Productivity is of high importance in any manufacturing operation. Inmany manufacturing operations, welding of workpieces is an important andintegral part of producing high quality assemblies. A number of weldingsystems have been used and are being developed, including gas metal arcwelding (GMAW), gas tungsten arc welding (GTAW), shielded metal arcwelding (SMAW), submerged arc welding (SAW), and so forth. And all ofthese may be used depending upon such factors as the parts to be joined,the size and thicknesses of the materials, the final assembly desired,and the materials used.

In some contexts, it has been proposed to utilize secondary heatsources, such as induction heating, in conjunction with welding systems.Such processes are sometimes referred to as “hybrid induction welding”processes. Hybrid induction welding can produce welds at higher speeds,with less pre-weld preparation, and using fewer consumables compared toprocesses such as arc welding alone. Moreover, supplemental heating canchange the cooling rate of the weld, which can improve the quality ofthe finished weld. All fusion welding processes, where a metal is meltedin order to form a weld joint, involve the application of, or generationof, heat in some form. Hybrid induction welding processes add heat froman induction heating head or source which improves the productivity.But, the addition of extra heat can be detrimental—some alloys aresensitive to temperature and higher temperatures or larger heated areascan be detrimental to the quality and properties of the weld or the heataffected zone adjacent to the weld. Added heat can cause increaseddistortion resulting in welds which must be straightened after the weld,or which require additional processing post-welding.

There continue to be needs for improvement in such hybrid inductionwelding processes, however, particularly for addressing such drawbacksin existing systems.

BRIEF DESCRIPTION

The present disclosure sets forth embodiments of metal working systemsand processes, such as welding systems and processes that improveperformance and efficiency by the use of induction heating. In certainembodiments, stresses and distortion may be controlled and reduced byusing induction heating and welding arc heating together. Certain novelarrangements of induction heating heads, coils, and configurations maycontribute to the improvements. Moreover, unique gas formulations, gasand wire combinations, and so forth, may be used due to the combinationof heating by the welding arc and the induction heating source.

DRAWINGS

These and other features, aspects, and advantages of the presentdisclosure will become better understood when the following detaileddescription is read with reference to the accompanying drawings in whichlike characters represent like parts throughout the drawings, wherein:

FIG. 1 is a block diagram of an exemplary welding system including aninduction heating system configured to increase temperatures of a weldlocation ahead of the welding process;

FIG. 2 is a block diagram illustrating exemplary functional componentsof the welding system and induction heating system of FIG. 1, inaccordance with aspects of the present disclosure;

FIG. 3 is a block diagram illustrating exemplary functional componentsof the induction heating system of FIG. 1, in accordance with aspects ofthe present disclosure;

FIG. 4 is a perspective view of internal components on an embodiment ofa hybrid induction heating/welding assembly, including an embodiment ofa protective housing that entirely surrounds an induction heating coil,in accordance with aspects of the present disclosure;

FIG. 5 is a perspective view of an embodiment of a protective housingthat is disposed between an induction heating coil and a correspondingflux concentrator material and a welding torch, in accordance withaspects of the present disclosure;

FIG. 6 is a perspective view of internal components of an embodiment ofthe hybrid induction heating/welding assembly, in accordance withaspects of the present disclosure;

FIGS. 7A and 7B are perspective views of internal components of anembodiment of the hybrid induction heating/welding assembly, inaccordance with aspects of the present disclosure;

FIG. 8 is a cross-sectional side view of an embodiment of a circular airknife and a water spray head of the hybrid induction heating/weldingassembly, in accordance with aspects of the present disclosure;

FIG. 9 is a side view of an embodiment of a protective housing of thehybrid induction heating/welding assembly, in accordance with aspects ofthe present disclosure;

FIG. 10 is a perspective view of the hybrid induction heating/weldingassembly of FIG. 9 coupled to mechanical motion systems, in accordancewith aspects of the present disclosure;

FIGS. 11A and 11B illustrate two induction heating coil configurationsfor butt joints, in accordance with aspects of the present disclosure;

FIGS. 12A through 12H illustrate various induction heating coilconfigurations for T-fillet joints, in accordance with aspects of thepresent disclosure;

FIGS. 13A and 13B illustrate various shapes of a weld backing for use inbutt joints and T-fillet joints, respectively, in accordance withaspects of the present disclosure;

FIGS. 14A and 14B illustrate a coil standoff distance between theinduction heating coil(s) of the hybrid induction heating/weldingassembly and the surface of workpieces, in accordance with aspects ofthe present disclosure;

FIGS. 15A and 15B illustrate various weld gap distances betweenworkpieces for butt joints and T-fillet joints, respectively, inaccordance with aspects of the present disclosure;

FIG. 16 illustrates a conventional welding operation in which a V-jointprofile is used, with the consequent loss of energy from the weldingarc;

FIG. 17 illustrates how the application of induction heating and archeating may be combined for balanced heating in a narrow gap weld, inaccordance with aspects of the present disclosure;

FIGS. 18A and 18B illustrates various induction heating coilconfigurations, in accordance with aspects of the present disclosure;

FIGS. 19A and 19B illustrates various configurations for multipleinduction heating coils, in accordance with aspects of the presentdisclosure;

FIG. 20 illustrates a narrow gap weld being performed using the hybridinduction arc welding processes in accordance with aspects of thepresent disclosure;

FIG. 21 illustrates a non-uniform heat profile that may be generated bya conventional butt welding arc, and the distortion of a workpiece fromits original shape to a distorted shape;

FIG. 22 illustrates a uniform heat profile that may be generated in abutt weld using the hybrid induction arc welding processes in accordancewith aspects of the present disclosure;

FIG. 23 illustrates a heat profile that may be generated by aconventional T-fillet welding arc, and the distortion of a workpiecefrom its original shape to a distorted shape; and

FIG. 24 illustrates a heat profile that may be generated in a T-filletweld using the hybrid induction arc welding processes in accordance withaspects of the present disclosure.

DETAILED DESCRIPTION

A hybrid induction metal working process is disclosed that utilizes aninduction heating source in conjunction with a metal working system,such as a welding system. While the embodiments are described herein aswelding processes, it should be born in mind that they may be metalworking processes more generally, such as cutting operations, claddingoperations, bending operations, heat treating operations, preparationand post working operations, and so forth. In at least some of theembodiments described, a GMAW process is assumed that utilizes one ormore welding power sources, one or more welding torches receiving powerand shielding gas, and one or more wire feeders that provides the neededpower, gas and welding wire electrode through the one or more weldingtorches.

Moreover, the disclosed embodiments may be used in conjunction with oneor more of the systems and processes set forth in the following, each ofwhich is hereby incorporated by reference in its entirety for allpurposes: U.S. patent application Ser. No. 13/111,433, entitled“AUXILIARY WELDING HEATING SYSTEM,” filed by Holverson et al. on May 19,2011; U.S. patent application Ser. No. 14/280,164, entitled “INDUCTIONHEATING SYSTEM,” filed by Beistle et al. on May 16, 2014; U.S. patentapplication Ser. No. 14/280,197, entitled “INDUCTION HEATING SYSTEMTEMPERATURE SENSOR ASSEMBLY,” filed by Verhagen et al. on May 16, 2014;U.S. patent application Ser. No. 14/280,227, entitled “INDUCTION HEATINGSYSTEM TRAVEL SENSOR ASSEMBLY,” filed by Garvey et al. on May 16, 2014;U.S. patent application Ser. No. 14/494,248, entitled “METAL HEATING ANDWORKING SYSTEM AND METHOD,” filed by Albrecht et al. on Sep. 23, 2014;U.S. patent application Ser. No. 14/532,695, entitled “LARGE SCALE METALFORMING,” filed by Jones et al. on Nov. 4, 2014; and U.S. patentapplication Ser. No. 14/705,738, entitled “LARGE SCALE METAL FORMINGCONTROL SYSTEM AND METHOD,” filed by Jones et al. on May 6, 2015.

Turning now to the drawings, FIG. 1 illustrates an exemplary weldingsystem 10 which powers, controls, and provides consumables to a weldingoperation. The welding system 10 includes a welding power supply 12 (ormultiple welding power supplies 12, in certain embodiments), a wirefeeder 14 (or multiple mire feeders 14, in certain embodiments), and awelding torch 16 (or multiple welding torches 16, in certainembodiments). The power supply 12 may be a power converter or aninverter based welding power supply (or multiple power supplies that maynot be the same type) requiring a power source 18. In certainembodiments, multiple power supplies 12 (of the same or different types)may be connected to one wire feeder 14 and welding torch 16. Manydifferent circuit designs may be provided in the power source 18, andmany different welding regimes may be envisaged (e.g., direct current,alternating current, pulsed, short circuit, etc. Any of theseconventional circuits and process technologies may be used inconjunction with the present induction heating techniques. In otherembodiments, the welding power supply 12 may be a generator oralternator welding power supply which may include an internal combustionengine. The welding power supply 12 may also include a user interface 20for adjusting various welding parameters such as voltage and current,and for connecting a power source 18, if required. Additionally, a gassource 22 may be coupled to the welding power supply 12. The gas source22 is the source of the shielding gas that is supplied to the weldingtorch 16. In addition, in certain embodiments, the gas source 22 alsosupplies shielding gas to an auxiliary shielding gas diffuser 24. Forexample, in certain embodiments, the gas source 22 may supply argon gas.As will be appreciated, the shielding gas is applied to the location ofthe liquid weld pool by the welding torch 16 and/or the auxiliary gasdiffuser 24 to prevent absorption of atmospheric gases which may causemetallurgical damage to the weld. As shown, the welding power supply 12is coupled to the welding wire feeder 14. For example, the welding powersupply 12 may be coupled to the welding wire feeder 14 by a feeder powerlead, a weld cable, a gas hose, and a control cable.

The welding wire feeder 14 shown in the illustrated embodiment provideswelding wire to the welding torch 16 for use in the welding operation. Avariety of welding wires may be used. For example, the welding wire maybe solid steel, solid aluminum, solid stainless steel, metal cored wire,flux cored wire, flat strip electrode, and so forth. The embodimentsdescribed herein may be used with any suitable type of electrode (orcold wire feed, in certain embodiments), and any suitable wirecomposition. Furthermore, the thickness of the welding wire may varydepending on the welding application for which the welding wire is used.For example, the welding wire may be 0.045″, 0.052″, 1/16″, 3/32″, ⅛″,or any other diameter. Furthermore, the welding wire feeder 14 mayenclose a variety of internal components such as a wire feed drivesystem, an electric motor assembly, an electric motor, and so forth. Thewelding wire feeder 14 may further include a control panel (not shown)that allows a user to set one or more wire feed parameters, such as wirefeed speed. In the illustrated embodiment, the auxiliary shielding gasdiffuser 24 is also coupled to the welding wire feeder 14 by a gas hose26 (or may be connected directly to the gas source and controlled fromthe user interface 20). However, the welding wire feeder 14 may be usedwith any wire feeding process including gas operations (gas metal arcwelding (GMAW)), gasless operations (shielded metal arc welding (SMAW)or self-shielding flux cored arc welding (FCAW)), submerged arc welding(SAW), and so forth.

As shown, the welding wire is fed to the welding torch 16 through afirst cable 28. The first cable 28 may also supply gas to the weldingtorch 16, and may also supply cooling water to the welding torch 16. Asfurther shown, a second cable 30 couples the welding power supply 12 toa workpiece 32 (typically via a clamp) to complete the circuit betweenthe welding power supply 12 and the welding torch 16 during a weldingoperation.

The exemplary welding system 10 also includes an induction heatingsystem 34. As mentioned above, the induction heating system 34 includesan induction heating coil 36 and an induction power supply 38. Theinduction power supply 38 includes a user interface 40. The userinterface 40 may include buttons, knobs, dials, and so forth, to allowan operator to regulate various operating parameters of the inductionpower supply 38. For example, the user interface 40 may be configured toenable an operator to set and adjust the frequency of the alternatingcurrent produced by the induction power supply 38. Similarly, the userinterface 40 may enable an operator to select a desired outputtemperature of the induction heating coil 36. The user interface 40 mayalso include one or more displays configured to provide system feedbackto the operator (e.g., real-time temperature of the induction heatingcoil 36, travel speed of the induction heating coil 36 relative to theworkpiece 32, and so forth). In certain embodiments, the induction powersupply 38 may be coupled to a step-down transformer 42 with electricalwire conductors 44. More specifically, two electrical wire conductors 44are routed from the induction power supply 38 to the transformer 42, andeach electrical wire conductor 44 is routed inside a flexible tube orconduit. Furthermore, the induction heating system 34 may be anair-cooled or a liquid-cooled system. For example, a coolant may flowinside the flexible tubes routing each of the electrical wire conductors44. In certain embodiments, one flexible tube routing an electrical wireconductor 44 contains a flowing coolant which enters the transformer 42,and another flexible tube routing an electrical wire conductor 44contains a flowing coolant which flows from the transformer 42 to a heatexchanger or other device that removes heat from the coolant.

The alternating electrical current exits the transformer 42 and issupplied to the induction heating coil 36 by electrical conductors 46.In certain embodiments, the electrical conductors 46 may have a hollowcore and may also route the flowing coolant through the inductionheating coil 36. In the illustrated embodiment, the induction heatingcoil 36 is disposed proximate to the workpiece 32. As the alternatingcurrent flows through the induction heating coil 36, eddy currents aregenerated and induced within the workpiece 32. The eddy currents flowagainst the electrical resistivity of the workpiece 32, therebygenerating localized heat in the workpiece 32. As shown, the inductionheating coil 36 is positioned ahead of the welding torch 16. In otherwords, for a welding torch 16 operating and traveling in a direction 48,the induction heating coil 36 is placed in front of the welding torch 16(i.e., along the weld joint and before a welding arc 50 created by thewelding torch 16). As a result, the induction heating coil 36 heats alocalized area 52 of the workpiece 32 immediately ahead of the weldingarc 50, thereby raising the temperature of the localized area 52 justahead of the welding arc 50. As will be appreciated by those skilled inthe art, such temperatures are generally substantially higher thanconventional “preheat” temperatures (and may reach as high as themelting point). Consequently, as the welding torch 16 travels in thedirection 48, less heat from welding arc 50 is needed to bring thelocalized area 52 of the workpiece 32 to melting temperature. Therefore,more heat generated by the welding arc 50 may be used to melt thewelding wire so that the welding wire may be fed to the welding arc athigher rates, which enables the welding torch 16 to complete the weld ofthe workpiece 32 at higher speeds. As such, the combination of featuresof the hybrid induction heating/welding assembly 90 described herein maylead to double (or even triple) the welding rate as compared tocomparable conventional welds.

As shown, the welding power supply 12 and the induction power supply 38may also be coupled in certain embodiments. For example, the weldingpower supply 12 and the induction power supply 38 may be coupled by ahard wire, through a wireless connection, over a network, and so forth.As discussed in detail below, the welding power supply 12 and theinduction power supply 38 may exchange data and information during theoperation of the exemplary welding system 10. More particularly, thewelding power supply 12 and the induction power supply 38 may functionin cooperation (e.g., utilize feedback from one another) to adjustvarious operating parameters of the exemplary welding system 10.

It should be noted that modifications to the exemplary welding system 10of FIG. 1 may be made in accordance with aspects of the presentdisclosure. Although the illustrated embodiments are described in thecontext of an arc welding process, the features of the presentembodiments may be utilized with a variety of other suitable welding orcutting systems and processes. For example, the induction heating system34 may be used with a plasma cutting system or with a plate bendingsystem. More specifically, the induction heating system 34 may bedisposed ahead of a plasma cutter to increase the temperature of alocalized area ahead of the plasma cut, thereby enabling increasedcutting speeds. Furthermore, while the induction heating system 34 ispositioned ahead of the welding torch 16 in the present embodiment, theinduction heating system 34 may be positioned in other locations. Forexample, the induction heating system 34 may be positioned behind thewelding torch 16 to provide a heat treatment to a weld location afterthe workpiece 32 is welded and fused. Similarly, certain embodiments mayinclude more than one induction heating system 34 or induction heatingcoil 36 (i.e., a first induction heating system 34 or induction heatingcoil 36 positioned ahead of the welding torch 16 to raise thetemperature of the localized area 52, a second heating system 34 orinduction heating coil 36 positioned behind the welding torch 16 toprovide a heat treatment of a weld location that has been fused), and/ora third heating system 34 or induction heating coil 36 to heat theworkpiece 32 ahead or behind of the welding process to reduce the rateof cooling of the weld to prevent metallurgical damage.

FIG. 2 is a block diagram illustrating certain of the internalcomponents of the exemplary welding system 10. As discussed above, thepower source 18 may power one or more welding power supplies 12 and/orone or more induction power supplies 38. Each welding power supply 12provides power to a welding wire feeder 14 or to the welding torch 16,and the welding power supply 12 is coupled to the workpiece 32, therebycompleting the circuit between the welding power supply 12 and thewelding torch 16 during a welding operation. Each induction power supply38 generates an alternating electrical current that is supplied to atransformer 42, which subsequently routes the current to an inductionheating coil 36. As mentioned above, the welding power supply 12 and theinduction power supply 38 may be coupled and configured to exchangeinformation and data (e.g., operating parameters, settings, user input,etc) to enable the welding power supply 12 and the induction powersupply 38 to function cooperatively.

The welding power supply 12 includes several internal components toregulate various operating parameters of the welding system 10. In theillustrated embodiment, the welding power supply 12 includes controlcircuitry 54, a processor 56, memory circuitry 58, and interfacecircuitry 60. The control circuitry 54 is configured to apply controlsignals to the welding power supply 12 and/or the welding wire feeder14. For example, the control circuitry 54 may provide control signals tothe welding wire feeder 14 relating to the voltage or current providedby the welding power supply 12. The control circuitry 54 may alsoprovide control signals for regulating the operation of the welding wirefeeder 14 such as pulse width modulated (PWM) signals to regulate a dutycycle for a motor assembly in the welding wire feeder 14, and so forth.

The control circuitry 54 is further coupled to the processor 56, memorycircuitry 58 and interface circuitry 60. The interface circuitry 60 iscoupled to the user interface 20 of the welding power supply 12. Asdiscussed above, the user interface 20 is configured to enable anoperator to input and control various settings of the welding powersupply 12. For example, the user interface 20 may include a menu forselecting a desired voltage or current output to the welding wire feeder14. Additionally, the user interface 20 may include a menu or list ofwelding processes or welding wire materials and diameters. As will beappreciated, different welding processes, welding wire materials, andwelding wire diameters may have different characteristics and mayrequire differing configurations for various operating parameters. Forexample, configuration parameters requiring differing values may includevoltage output, current output, wire feed speed, wire feed torque, andso forth. Preset values for such configuration parameters, as well asothers, may be stored in the memory circuitry 58 for each of a varietyof welding processes, welding wire materials, and welding wirediameters.

By way of example, a user may select a welding process from a menu of aplurality of different welding processes displayed on the user interface20 of the welding power supply 12. The user interface 20 communicatesthe selection of the welding process to the interface circuitry 60,which communicates the selection to the processor 56. The processor 56then retrieves the particular configuration parameters for the weldingprocess stored in the memory circuitry 58. Thereafter, the processor 56sends the configuration parameters to the control circuitry 54 in orderthat the control circuitry 54 may apply appropriate control signals tothe welding wire feeder 14. In certain embodiments, as discussed below,the control circuitry 54 of the welding power supply 12 may alsocommunicate the configuration parameters to the induction power supply38.

In the illustrated embodiment, the induction power supply 38 includescontrol circuitry 62, a processor 64, memory circuitry 66, and interfacecircuitry 68. The control circuitry 62 is configured to apply controlsignals to the induction power supply 38 and/or the transformer 42. Forexample, the control circuitry 62 may provide control signals relatingto the alternating electrical current (e.g., alternating currentfrequency) supplied by the induction power supply 38 to the transformer42. Additionally, the control circuitry 62 may regulate the operation ofa cooling system used with the induction power supply 38 and/or thetransformer 42. As mentioned above, the induction heating system 34 mayuse air or a coolant to provide circulating cooling throughout theinduction heating system 34. For example, the control circuitry 62 mayregulate a flow of a liquid coolant through the transformer 42 and theinduction heating coil 36 to maintain a desired temperature of theinduction heating system 34.

The control circuitry 62 is further coupled to the processor 64, memorycircuitry 66, and interface circuitry 68. The interface circuitry 68 iscoupled to the user interface 40 of the induction power supply 38. Asmentioned above, the user interface 40 of the induction power supply 38enables an operator to regulate one or more operating parameters orsettings of the induction power supply system 38. For example, the userinterface 40 may enable a user to select a particular design of theinduction heating coil 36 from a menu of designs. As will beappreciated, different induction heating coil 36 designs may havedifferent configuration parameters. For example, different designs mayhave different maximum operating temperatures, and may require differentfrequencies of alternating current to achieve a desired temperature.Similarly, the coolant used to cool the induction heating system 34 mayhave different configuration parameters (e.g., heat transfercoefficients, viscosities, flow rates, and so forth). Preset values forsuch configuration parameters, as well as others, may be stored in thememory circuitry 66. For example, the user interface 40 may communicatea user selection of the induction heating coil 36 designs to theinterface circuitry 68, which may communicate the selection to theprocessor 64. The processor 64 may then retrieve the particularconfiguration parameters for the induction heating coil 36 stored in thememory circuitry 66. Thereafter, the processor 64 sends theconfiguration parameters to the control circuitry 62 in order that thecontrol circuitry 62 may apply appropriate control signals to theinduction power supply 38 and the transformer 42.

As mentioned above, the welding power supply 12 and the induction powersupply 38 may be coupled to one another by a hard wire, wirelessconnection, network connection, or the like. In particular, the weldingpower supply 12 and the induction power supply 38 may be configured tosend and receive data and information to one another relating to theoperating of the welding system 10. For example, the welding powersupply 12 and the induction power supply 38 may communicate with oneanother to coordinate the speed of the induction heating coil 36 and thewelding torch 16 along the workpiece 32. As described herein, in certainembodiments, the induction heating coil 36 and the welding torch 16 areboth designed for automated operation. As a result, the welding powersupply 12 and the induction power supply 38 may be coupled andconfigured to communicate and actively adjust a distance between theinduction heating coil 36 and the welding arc 50, as the inductionheating coil 36 and the welding torch 16 travel along the workpiece 32in the direction 48. For example, in certain embodiments, the weldingtorch 16 and the induction heating coil 36 may each have sensorsconfigured to measure a travel speed or temperature along the workpiece32.

For further example, the welding power supply 12 may communicate a userselected welding process (i.e., a welding process selected by anoperator through the user interface 20) to the induction power supply38. More specifically, the control circuitry 54 of the welding powersupply 12 may communicate the welding process selection to the controlcircuitry 62 of the induction power supply 38. Thereafter, the controlcircuitry 62 of the induction power supply 38 may modify any of avariety of operating parameters based on the user selected weldingprocess. For example, the control circuitry 62 may begin or end theprocess, or regulate the frequency or amplitude of the alternatingcurrent provided to the induction heating coil 36 or the flow rate of acoolant through the transformer 42 and/or the induction heating coil 36to achieve a desired maximum temperature of the induction heating coil36 based on the welding process selected. More specifically, for aselected welding process, the processor 64 may retrieve configurationparameters for the selected welding process from the memory circuitry 66and send the configuration parameters to the control circuitry 62.Similarly, the control circuitry 62 of the induction power supply 38 maysend operating information or data to the control circuitry 54 of thewelding power supply 12. For example, the control circuitry 62 may sendtemperature data (e.g., maximum temperature or real-time temperature) ofthe induction heating coil 36 to the control circuitry 54 of the weldingpower supply 12. Thereafter, the control circuitry 54 of the weldingpower supply 12 may adjust one or more operating parameters of thewelding power supply and/or welding wire feeder 14 in response to thedata received from the induction power supply 38. For example, thecontrol circuitry 54 of the welding power supply 12 may begin or end thewelding process or adjust the wire feed speed or torque of the weldingwire feeder 14 based on the temperature data of the induction heatingcoil 36 received from the control circuitry 62 of the induction powersupply 38. As will be appreciated, for higher temperatures provided bythe induction heating coil 36 to the localized area 52 of the workpiece32 ahead of the welding arc 50, a slower or faster wire feed speed maybe needed.

It should be noted that in certain embodiments, the power supplies andcontrol circuits used for generation and control of induction heatingpower and welding power may be joined. That is, some or all of thecircuits may be provided in a single power supply, and certain of thecircuits may serve both functions (e.g., operator interface components).Additionally, a central controller may provide coordination andsynchronization commands to both the welding/cutting system and theinduction system.

It should also be noted that while reference is sometimes made in thepresent disclosure to advancement or movement of the welding torch 16and adjacent induction heating system 34, depending upon the weldingsystem design, the welding torch 16 and the induction heating system 34may indeed be displaced, while in other systems these may remaingenerally stationary, with the workpiece or workpieces being moved. Suchmay be the case, for example, in certain robotic or automatedoperations, in submerged arc applications, and so forth. Both scenariosare intended to be covered by the present disclosure, and references tomoving the welding torch 16 and the induction heating system 34 shouldbe understood to include any relative motion between these componentsand the workpiece(s) 32.

FIG. 3 is a block diagram of an embodiment of the induction heatingsystem 34 of FIG. 1, illustrating the induction power supply 38, thestep-down transformer 42, and the induction heating coil 36 positionedahead of the welding arc 50 produced by the welding torch 16. Asdiscussed above, the transformer 42 is coupled to the induction powersupply 38 by electrical wire conductors 44. The induction power supply38 supplies an alternating current to the transformer 42 through theelectrical wire conductors 44. From the transformer 42, the alternatingcurrent is supplied to the induction heating coil 36 by electricalconductors 46. Specifically, the alternating current exits thetransformer 42 through power connections 70 attached to a base 72 of thetransformer 42. The electrical conductors 46 are coupled to the powerconnections 70, e.g., by soldering, brazing, or bolting. As mentionedabove, in certain embodiments, the electrical conductors 46 may have ahollow core, thereby enabling a coolant to flow through the electricalconductors 46 and the induction heating coil 36 to regulate a maximumtemperature of the induction heating coil 36. In other words, theelectrical conductors 46 and the induction heating coil 36 may carry thealternating current and a coolant flow.

As shown, the transformer 42 is supported by a top plate 74 and a bottomplate 76. In certain embodiments, the top and bottom plates 74 and 76may be formed from a ceramic or other electrically insulating material.The top and bottom plates 74 and 76 are further coupled to a metal,ceramic, or polymer frame 78. The metal, ceramic, or polymer frame 78may be configurable such that a distance 80 between the workpiece 32 andthe induction heating coil 36 can be adjusted. For example, the metalframe 78 may further be secured to a robotic manipulator 88 (e.g., see,FIG. 2) configured to move and guide the induction heating system 34 inmultiple planes along the weld joint of the workpiece 32. Furthermore,the robotic manipulator 88 may be coupled to the control circuitry 62 ofthe induction power supply 38 such that the control circuitry 62 mayregulate the movement and speed of the induction heating coil 36 and/orthe entire induction heating system 34 relative to the workpiece 32.

The purpose of the induction heating coil 36 is to carry electricalcurrent from the transformer 42 or power supply 12 to the part (e.g.,the workpiece 32) which is to be heated. The induction heating coil 36is essentially a direct electrical short circuit between the two polesof the transformer 42 or the power supply 12. If any damage occurs tothe induction heating coil 36, it may quickly overheat at the damagedarea and melt. In certain embodiments, the induction heating coil 36 maybe a metal tube which has been bent or formed or fabricated into a shapewhich will heat the part (e.g., the workpiece 32). Water or othercoolant flows through the interior of the induction heating coil 36 tokeep the induction heating coil 36 from overheating. If the coolantreaches the boiling point such that a gas bubble is formed on theinterior surface of the induction heating coil 36, that gas bubble formsa barrier which prevents the coolant from removing heat from that areaof the coil interior surface. If not monitored, the induction heatingcoil 36 may be damaged by localized melting at the location of thatbubble. For example, a small indentation or a bending of the inductionheating coil 36 into a shape different that the original design shape,may cause turbulence in the flow or a stagnant area of coolant flow,which is a possible location for the coolant to heat to above theboiling point. Also, cold working of a metal will decrease theelectrical conductivity of the induction heating coil 36 at the localarea of deformation, which can cause that spot on the induction heatingcoil 36 to overheat.

The electrical conductivity property of the induction heating coil 36 isan important physical characteristic. Any resistance heating of theinduction heating coil 36 will reduce the efficiency of the inductionheating process. Energy which is used to resistance heat the inductionheating coil 36 may then be lost to the coolant, and not available toheat the part (e.g., the workpiece 32). The electrical conductivity of ametal is reduced by bending or forming, and by alloying ingredients. Thecoil metal, if it is bent or formed during fabrication, will have theelectrical resistance increased in that area of deformation. A lowerstrength metal will exhibit a lesser decrease in conductivity whendeformed than a higher strength metal. So, the induction heating coil 36may be fabricated from a pure or nearly pure metal in the loweststrength mechanical condition. Consequently, in certain embodiments, theinduction heating coil 36 is protected from any bending or othermechanical damage.

In particular, as illustrated in FIG. 4, in certain embodiments, theinduction heating coil 36 may be protected by using an outer sheath orstructure as a coil protective housing 82. For example, in certainembodiments, the induction heating coil 36 may be entirely surrounded bythe coil protective housing 82. Such a structure must not beelectrically conductive to prevent heating by the induction heating coil36. Higher strength polymer and ceramic materials may be used to preventmechanical damage to the induction heating coil 36. Ceramic materialsmay be shaped prior to firing and polymer materials may be cast ormachined to provide support to prevent damage to the induction heatingcoil 36. For example, in certain embodiments, the coil protectivehousing 82 may be a single piece, or a multiple piece structure. Amultiple piece structure may be made from pieces which are all the samematerial, or may be made from a plurality of pieces, each of which canbe different materials or the same materials. For example, in certainembodiments, the coil protective housing 82 may be made from two piecesof high density polypropylene, so the two pieces could be taken apartand easily removed and replaced. Additionally, if heat radiating fromthe heated part (e.g., the workpiece 32) is sufficient to cause damageto the coil protective housing 82, then multiple pieces may be used,where part of the coil protector housing 82 is made from a ceramicmaterial that can withstand the heat near the heated part (e.g., theworkpiece 32). Some ceramic materials are susceptible to heating byinduction. In the case of the use of these types of ceramics, theceramic material of the coil protective housing 82 may be shielded fromthe electromagnetic radiation generated by the passage of electricalcurrent through the induction heating coil 36. In such embodiments, anelectromagnetic flux concentrator material 84 may be placed between theinduction heating coil 36 and the ceramic piece or pieces of the coilprotective housing 82.

When the induction heating coil 36 is being used to produce a heatedspot or heated line in the case of a thermal forming process, to producea heated line ahead of the welding torch 16 in the case of hybridinduction arc welding, or to produce a heated line ahead of a cuttingtorch in the case of hybrid induction cutting, additional ceramicmaterial may be added to further protect the induction heating coil 36from the heat of the process. The choice of the material may depend onthe specific properties of the material, such as wear resistance,resistance to erosion by flowing liquid metal or liquid metal oxides orother heated material, or resistance to the radiative heat of a weldingarc or a plasma cutting arc. The susceptibility to heating by theinduction heating coil 36 is a secondary material property while thewear, resistance to erosion, or the resistance to radiative heat from anarc (e.g., the welding arc 50) is the primary property upon which thematerial selection is made. Such ceramic components used to protect theinduction heating coil 36 may, themselves, be protected from heating bythe induction heating coil 36, by placement of flux concentratormaterial in the path of the radiated electromagnetic field produced bythe induction heating coil 36 to prevent the electromagnetic field fromaffecting the ceramic material.

For example, FIG. 5 illustrates an embodiment of an induction heatingcoil 36 with a ceramic coil protective housing 82 using the fluxconcentrator material 84 between the induction heating coil 36 and theceramic coil protective housing 82. More specifically, as illustrated inFIG. 5, in certain embodiments, the flux concentrator material 84 may bedisposed around the induction heating coil 36 The flux concentratormaterial 84 utilized to reduce or prevent wear and other degradation inthis way may include materials that are heat resistant, non-metallic,wear resistant, and electrically insulating such as fiber reinforcedmaterials, tempered glasses or composites.

Another method to prevent damage to the induction heating coil 36 is tosense that the induction heating coil 36 is likely to be damaged bycollision, and to activate a motion device or multiple motion devices toprevent the collision and the damage. For example, as illustrated inFIG. 6, in certain embodiments, one or more sensors 86 may be used toprotect the coil from collision and damage. For example, in certainembodiments, a laser height/distance sensor 86 (or otherposition-detecting sensor) may be used for sensing to prevent theinduction heating coil 36 from colliding with a non-flat surface as itis moved along near the surface or to prevent the induction heating coil36 from colliding with objects protruding from the surface.

As illustrated in FIG. 2, in certain embodiments, a robotic manipulator88 or other mechanical motion system may be controlled by signals fromthe one or more sensors 86 to move the induction heating coil 36 toavoid collision with an object. It is also possible to use multiplelaser distance sensors 86, or to have one or more laser distance sensors86 pointing in different directions, or onto a curved surface atdifferent locations, to provide data input to control circuitry (e.g.,the control circuitry 54, 62 of the welding power supply 12 and theinduction power supply 38, respectively, or some other control circuitryof the system 10), and for the control circuitry 54, 62 to controlmultiple robotic manipulators 88 or other mechanical motion systems toprevent collision with a curved surface, but to maintain a constantstand-off distance of the induction heating coil 36 from the surface.Alternative collision detection methods are possible, including a jointthat detects a small degree of flexing. Reaching the small degree offlex, the motion may be stopped to prevent damage. In addition, sensinga higher than normal force in the system 10 may be used to sense acollision and stop the system 10 before damage occurs.

In addition, in certain embodiments, the control circuitry (e.g., thecontrol circuitry 54, 62 of the welding power supply 12 and theinduction power supply 38, respectively, or some other control circuitryof the system 10) may control the multiple robotic manipulators 88 orother mechanical motion systems to independent control position,orientation, and/or movement of the welding torch 16 and the transformer42 and/or the induction heat coil 36 relative to the workpieces 32 beingworked on. For example, the robotic manipulators 88 or other mechanicalmotion systems may include independent positioning systems disposedwithin a common housing (see, e.g., the housing 134 illustrated in FIGS.9 and 10) of the hybrid induction heating/welding assembly 90 (see,e.g., FIGS. 7A, 7B, 9, and 10). More specifically, in certainembodiments, the independent positioning systems disposed within thecommon housing 134 of the hybrid induction heating/welding assembly 90may include multi-axis positioning systems configured to independentlyadjust the position, orientation, and/or movement of the welding torch16 and the transformer 42 and/or the induction heat coil 36 relative tothe common housing 134 (and, thus, relative to the workpieces 32 beingworked on. Accordingly, these multi-axis positioning systems form a partof the robotic manipulators 88 or other mechanical motion systemsdescribed herein.

If the induction heating coil 36 moves too far from the surface of thepart (e.g., the workpiece 32) being heated by the induction heating coil36, then the electromagnetic field coupling with the metal part will bereduced, and the energy transfer will be reduced. This condition maycause the induction heating coil 36 to overheat, and to potentially bedamaged. In this instance, the one or more laser distance sensors 86protect the induction heating coil 36 from overheating.

In certain embodiments, a circular air knife 92 may be used to direct acurtain of air to the surface of the metal being formed (e.g., theworkpiece 32). FIGS. 7A and 7B illustrate two separate perspective viewsof embodiments of internal components of an induction heating headassembly 90 in accordance with aspects of the present disclosure. Asillustrated, the induction heating coil 36 is used with a circular airknife 92 and water spray head 94. In the illustrated embodiment, theinduction heating coil 36 is a circular coil surrounded by anelectromagnetic field flux concentrator 84. However, otherconfigurations of the induction heating coil 36 and the electromagneticfield flux concentrator 84 may also be used in conjunction with acircular air knife 92 as described herein.

FIG. 8 is a cross-sectional side view of an embodiment of the circularair knife 92 and the water spray head 94. It will be appreciated thatother configurations of the circular air knife 92 and the water sprayhead 94 may be used in different embodiments. In the embodimentillustrated in FIG. 8, the circular air knife 92 has a frustoconicalshape, and the frustoconical air knife 92 is surrounded by the waterspray head 94, which supplies a water spray that follows the pathillustrated by arrows 96, 98 down to the workpiece 32. It should benoted that, although described herein as using water, other coolants(e.g., liquified gases such as liquid argon, solidified gases such ascarbon dioxide snow, and so forth) may be used instead of water,especially to increase the cooling rate of metals that may be reactiveto water.

In the illustrated embodiment, air 110 is delivered by an internalpassage 102 that starts the air 110 on a downward path, then diverts theair flow radially inward toward the center of the frustoconical airknife 92, as illustrated by arrows 104. At the opening adjacent to thefrustoconical air knife 92, the air delivery device passage 102 narrowsand forms an air sheet which develops flow that conforms to a curvedsurface that the air sheet follows. The curvature of the surface ends atthe same angle of flow as the corresponding frustoconical air knife 92such that the sheet of flowing air 110 then transfers to, and follows,the surface of the frustoconical air knife 92 down to the workpiece 32.The frustoconical air knife 92 surrounds the induction heating coil 36,which is held adjacent to the workpiece 32, forming a heated area on theworkpiece 32. The water spray following the path illustrated by arrows76, 78 is directed away from the heated area on the workpiece 32 by theair flow illustrated by arrows 106, 108, 110.

As such, the frustoconical air knife 92 maintains the temperature of themetal, preventing the spread of heat to the surrounding material byconduction. The frustoconical shape of the circular air knife 92 (i.e.,with the smaller end proximate the workpiece 32) provides a slightincrease in local air pressure at the surface of the workpiece 32,thereby forcing the flow of air as the circular air knife 92 impinges onthe workpiece 32, outward—preventing any of the water droplets from thesurrounding water curtain from splashing and hitting the workpiece 32inside the circular air knife 92. The relatively dry spot on theworkpiece 32 inside the ring of impingement of the circular air knife 92is where the induction heating coil 36 produces a heated spot. This dryarea has two important objectives: 1) any water on the surface of theworkpiece 32 reduces the heating efficiency of the induction; and 2)water on the surface of the workpiece 32 disrupts the reflected laserlight from the surface of the workpiece 32, causing the one or morelaser distance sensors 86 to detect erroneous height readings, which areused to control the robot manipulator 88 to maintain an optimum standoffdistance of the induction heating coil 36.

Returning now to FIGS. 7A and 7B, as illustrated, the hybrid inductionheating/welding assembly 90 includes the one or more laser heightsensors 86 disposed adjacent the circular air knife 92 and/or the sprayhead 94 such that the one or more laser height sensors 86 may detect adistance (height) of the one or more laser height sensors 86 from asurface of the part being heated (e.g., the workpiece 32), whereby thisdistance may be used as a proxy for determining the position of theinduction heating coil 36 from the surface of the part being heated(e.g., the workpiece 32). More specifically, the one or more laserheight sensors 86 may be communicatively coupled to control circuitry(e.g., the control circuitry 54, 62 of the welding power supply 12 andthe induction power supply 38, respectively, or some other controlcircuitry of the system 10), and the control circuitry 54, 62 mayreceive a signal from the one or more laser height sensors 86, anddetermine how to control operation of the hybrid inductionheating/welding assembly 90 accordingly. For example, as describedherein, the control circuitry 54, 62 may control multiple roboticmanipulators 88 or other mechanical motion systems to prevent collisionof the induction heating coil 36 with the surface of the part beingheated (e.g., the workpiece 32), and maintain a constant stand-offdistance of the induction heating coil 36 from the surface of the partbeing heated (e.g., the workpiece 32).

As illustrated in FIGS. 7A and 7B, in certain embodiments, the hybridinduction heating/welding assembly 90 may include a separate laserheight sensor module 112 (e.g., disposed within a housing of the hybridinduction heating/welding assembly 90) that is communicatively coupledto the one or more laser height sensors 86, and the laser height sensormodule 112 may be configured to receive a signal from the one or morelaser height sensors 86, and to determine how to control operation ofthe hybrid induction heating/welding assembly 90 accordingly. Forexample, the laser height sensor module 112 may include its own controlcircuitry (e.g., one or more processors configured to execute codestored in one or more storage media, similar to the control circuitry54, 62 described herein) for determining a distance of the inductionheating coil 36 from the surface of the part being heated (e.g., theworkpiece 32), and for at least partially controlling operation of thehybrid induction heating/welding assembly 90 accordingly (e.g., eitherindividually controlling or providing coordinated control with thecontrol circuitry 54, 62 of the welding power supply 12 and theinduction power supply 38, respectively, or some other control circuitryof the system 10). For example, the laser height sensor module 112 maybe configured to send control signals to multiple robotic manipulators88 or other mechanical motion systems to prevent collision of theinduction heating coil 36 with the surface of the part being heated(e.g., the workpiece 32), and to maintain a constant stand-off distanceof the induction heating coil 36 from the surface of the part beingheated (e.g., the workpiece 32).

In addition, in certain embodiments, the hybrid inductionheating/welding assembly 90 may include an infrared temperature sensormodule 114 (e.g., disposed within a housing of the hybrid inductionheating/welding assembly 90) that includes one or more infraredtemperature sensors, and is configured to determine how to controloperation of the hybrid induction heating/welding assembly 90accordingly. For example, the infrared temperature sensor module 114 mayinclude its own control circuitry (e.g., one or more processorsconfigured to execute code stored in one or more storage media, similarto the control circuitry 54, 62 described herein) for determiningtemperatures proximate the induction heating coil 36 and/or the surfaceof the part being heated (e.g., the workpiece 32), and for at leastpartially controlling operation of the hybrid induction heating/weldingassembly 90 accordingly (e.g., either individually controlling orproviding coordinated control with the control circuitry 54, 62 of thewelding power supply 12 and the induction power supply 38, respectively,or some other control circuitry of the system 10). For example, theinfrared temperature sensor module 114 may be configured to send controlsignals to the control circuitry 54 of the welding power supply 12and/or the control circuitry 62 of the induction power supply 38 toadjust the welding and/or induction power supplied to the hybridinduction heating/welding assembly 90 by the welding power supply 12and/or the induction power supply 38, to send control signals to controlposition, orientation, and/or movement of the hybrid inductionheating/welding assembly 90 relative to the surface of the part beingheated (e.g., the workpiece 32), to adjust flow rates and/ortemperatures of air and/or coolant delivered by the hybrid inductionheating/welding assembly 90 to the surface of the part being heated(e.g., the workpiece 32), and so forth.

In addition, in certain embodiments, the hybrid inductionheating/welding assembly 90 may include a compressed air manifold 116configured to deliver compressed air to the surface of the part beingheated (e.g., the workpiece 32). For example, in certain embodiments,one or more air valves 118 may be controlled such that flow rates of oneor more air flow streams (e.g., the air 100 guided by the frustoconicalair knife 92 illustrated in FIG. 8) delivered to the surface of the partbeing heated (e.g., the workpiece 32) may be controlled.

In addition, in certain embodiments, the hybrid inductionheating/welding assembly 90 may include one or more air flow sensors 120configured to detect flow rates of the air flow streams (e.g., the air100 guided by the frustoconical air knife 92 illustrated in FIG. 8)delivered to the surface of the part being heated (e.g., the workpiece32). The one or more air flow sensors 120 may be communicatively coupledto control circuitry (e.g., the control circuitry 54, 62 of the weldingpower supply 12 and the induction power supply 38, respectively, or someother control circuitry of the system 10), and the control circuitry 54,62 may receive a signal from the one or more air flow sensors 120, anddetermine how to control operation of the hybrid inductionheating/welding assembly 90 accordingly, for example, by manipulatingthe one or more air flow valves 118 to adjust flow rates of the air flowstreams delivered to the surface of the part being heated (e.g., theworkpiece 32).

In addition, in certain embodiments, the hybrid inductionheating/welding assembly 90 may include a water manifold 122 configuredto deliver water (or other coolant) to the surface of the part beingheated (e.g., the workpiece 32), for example, through the spray head 94.In addition, in certain embodiments, the hybrid inductionheating/welding assembly 90 may include one or more water flow sensors124 and/or one or more water temperature sensors 126 configured todetect flow rates and/or temperatures, respectively, of the water flowstreams (e.g., the water spray 96, 98 illustrated in FIG. 8) deliveredto the surface of the part being heated (e.g., the workpiece 32). Theone or more water flow sensors 124 and/or one or more water temperaturesensors 126 may be communicatively coupled to control circuitry (e.g.,the control circuitry 54, 62 of the welding power supply 12 and theinduction power supply 38, respectively, or some other control circuitryof the system 10), and the control circuitry 54, 62 may receive signalsfrom the one or more water flow sensors 124 and/or the one or more watertemperature sensors 126, and determine how to control operation of thehybrid induction heating/welding assembly 90 accordingly, for example,by adjusting flow rates and/or temperatures of the water flow streamsdelivered to the surface of the part being heated (e.g., the workpiece32).

As described herein, in certain embodiments, all of the componentsillustrated in FIGS. 7A and 7B may be disposed within a single housingof the hybrid induction heating/welding assembly 90. To that end, asillustrated in FIG. 7A, in certain embodiments, the hybrid inductionheating/welding assembly 90 may include composite mounts 128 formounting the transformer 42 to a mounting bracket 130 of the hybridinduction heating/welding assembly 90. Various brackets 132 providesupport for many of the other components of the hybrid inductionheating/welding assembly 90 and, as illustrated in FIG. 7B, provide asupport structure for the housing 134 of the hybrid inductionheating/welding assembly 90, within which the welding torch 16 and theone or more induction heating coil(s) 36 (as well as the other internalcomponents illustrated in FIGS. 4-8) may be at least partially enclosed.

FIG. 9 is a side view of the protective housing 134 of the hybridinduction heating/welding assembly 90. The protective housing 134 may becomprised of many different protective materials including, but notlimited to, high density polypropylene, ceramic, plexiglass, or otherprotective materials. In addition, in certain embodiments, the hybridinduction heating/welding assembly 90 may include an access cover 136configured to facilitate access to the internal components of the hybridinduction heating/welding assembly 90 (which are illustrated in FIGS. 7Aand 7B). For example, in the illustrated embodiment, the access cover136 is configured to swing open, as illustrated by arrow 138.

As also illustrated in FIG. 9, in certain embodiments, the hybridinduction heating/welding assembly 90 may also include a motorized mount140 disposed externally from the protective housing 134. In certainembodiments, the motorized mount 140 facilitates 360° of rotation of thehybrid induction heating/welding assembly 90 (e.g., around an axis 142,as illustrated by arrow 144). For example, the motorized mount 140 mayinclude a motor configured to cause rotation that facilitates therotation of the hybrid induction heating/welding assembly 90. Inaddition, the motorized mount 140 of the hybrid inductionheating/welding assembly 90 facilitates coupling of the hybrid inductionheating/welding assembly 90 to the multiple robotic manipulators 88 orother mechanical motion systems described herein (see, e.g., FIG. 2).For example, FIG. 10 is a perspective view of the hybrid inductionheating/welding assembly 90 coupled to mechanical motion systems 146,148. In certain embodiments, a first mechanical motion system 146 mayfacilitate x- and y-axis linear motion of the motorized mount 140 of thehybrid induction heating/welding assembly 90, whereas a secondmechanical motion system 148 may facilitate z-axis motorized motion ofthe motorized mount 140 of the hybrid induction heating/welding assembly90.

Returning now to FIG. 6, although described as being a welding torch 16being used for a hybrid induction arc welding process, in otherembodiments, the welding torch 16 may instead be replaced by a plasmacutting torch being used for a hybrid induction cutting process, orother hybrid metal working and induction heating processes may beimplemented using other types of metal working tools. Indeed, in certainembodiments, the welding torch 16 (and plasma cutting torches, etc.) maybe removable and replaceable from the hybrid induction heating/weldingassembly 90 (i.e., leaving the rest of the internal components of thehybrid induction heating/welding assembly 90 unchanged) such thatdifferent hybrid induction heating processes may be implemented by thehybrid induction heating/welding assembly 90 with relatively minimaleffort.

In addition to having removable and replaceable welding torches 16and/or plasma cutting torches, etc., in certain embodiments, theinduction heating coil 36 of the hybrid induction heating/weldingassembly 90 may also be removable and replaceable. Indeed, in certainembodiments, multiple induction heating coils 36 may be installed intothe hybrid induction heating/welding assembly 90 to facilitate differentconfigurations of parts (e.g., workpieces 32) being welded, cut, formed,etc. For example, FIGS. 11A and 11B illustrate two induction heatingcoil 36 configurations for butt joints. As illustrated in FIG. 11A, incertain embodiments, a single induction heating coil 36 may be disposedon a first side of parts (e.g., workpieces 32) being welded. In otherembodiments, a first induction heating coil 36 may be disposed on afirst side of parts (e.g., workpieces 32) being welded, whereas a second(e.g., back side) induction heating coil 36 may be disposed on a second,opposite side (e.g., back side) of the parts (e.g., workpieces 32) beingwelded. FIGS. 12A through 12H illustrate various induction heating coil36 configurations for T-fillet joints.

In certain embodiments, a weld backing 150 may be used in conjunctionwith the hybrid induction heating/welding assembly 90. Morespecifically, as illustrated in FIG. 13A, in the context of butt joints,the weld backing 150 may be disposed on a side of the parts (e.g.,workpieces 32) being welded opposite from an induction heating coil 36of the hybrid induction heating/welding assembly 90. FIG. 13A alsoillustrates various shapes of the weld backing 150 for use in buttjoints. Similarly, as illustrated in FIG. 13B, in the context ofT-fillet joints, the weld backing 150 may be disposed on a side of oneof the parts (e.g., workpieces 32) being welded opposite from aninduction heating coil 36 of the hybrid induction heating/weldingassembly 90. FIG. 13B also illustrates an exemplary shape of the weldbacking 150 for use in T-fillet joints. The weld backings 150illustrated in FIGS. 13A and 13B may be made of a variety of materialsincluding, but not limited to, copper, water-cooled copper, ceramic,powdered flux, fiberglass, woven fiber glass cloth, and so forth.

As described herein, the hybrid induction heating/welding assembly 90may include various sensors and/or sensor modules configured to detectoperational parameters of the hybrid induction heating/welding assembly90 (e.g., position, orientation, and/or movement of the inductionheating coil(s) 36 of the hybrid induction heating/welding assembly 90relative to a surface of the workpiece(s) 32, air and/or coolant flowrates and/or temperatures, welding power, induction heating power, andso forth), and to send signals to control circuitry (e.g., the controlcircuitry 54, 62 of the welding power supply 12 and the induction powersupply 38, respectively, or some other control circuitry of the system10) for the purpose of adjusting the operational parameters. Forexample, as illustrated in FIGS. 14A and 14B, in certain embodiments,the distance 152 between the induction heating coil(s) 36 of the hybridinduction heating/welding assembly 90 and the surface of the workpieces32 (referred to as the “coil standoff distance”) may be continuallyadjusted, for example, by the one or more robotic manipulators 88 orother mechanical motion systems described herein (see, e.g., FIG. 2)based at least in part on feedback from the various sensors and/orsensor modules of the hybrid induction heating/welding assembly 90. Inaddition, as illustrated in FIGS. 15A and 15B, in certain embodiments,the distance 154 between workpieces 32 (referred to as “weld gapdistance”) may be continually adjusted, for example, by the one or morerobotic manipulators 88 or other mechanical motion systems describedherein (see, e.g., FIG. 2) based at least in part on feedback from thevarious sensors and/or sensor modules of the hybrid inductionheating/welding assembly 90.

The hybrid induction metal working processes described herein preciselyplace the added heat, speed up the process so that, for example, theweld and base metal do not have added heat per unit length of weld, andplace the heat where it reduces the distortion and distortion-relatedproblems. By utilizing the induction heat to raise the surfaces of theweld joint up to a higher temperature, or even near melting, the heat ofthe welding arc can be utilized to melt the wire, and the process canrun at much higher travel speed than conventional welding. The arc canbe mostly contained in a narrow weld joint gap, thus much less of thearc energy is lost to the surrounding environment, resulting in muchmore efficient use of the energy in the arc plasma. Welding defects,which require labor and materials, as well as schedule time, arereduced, thus resulting in higher overall productivity. Moreover, whenusing conventional welding techniques, narrow gap welding is a problemusing only the welding arc for heat—gaps need to be fairly wide, andgenerally need to be wider at the top to accommodate the welding arc.With the improved hybrid induction metal working processes describedherein, a much narrower gap can be used, because the arc can easily meltinto the weld edges, which are already closer to the melting point,rather than having to machine or grind the weld joint to open the top.

Productivity is also increased because the narrow gap results in areduced use of consumables. The volume of metal needed to fill the weldjoint gap is supplied by the melted welding wire. A narrower gap will,necessarily, reduce the welding wire consumption—essentially replacingwhat, using conventional welding gaps, would have been expensive weldingwire with the much less expensive base metal of the parts (e.g., theworkpieces 32) being joined. A narrow gap reduces the amount ofshielding gas or flux as well. Consequently, productivity, which may beexpressed as a measure of the ratio of length of weld produced per unitcost, is increased. Additionally, the wear and damage to the weldingtorch 16, particularly the replacement parts, is generally measured bythe total “arc-on” time. The added speed of the process, reduces theamount of time the arc is on, thus reducing the wear and damage to thewelding torch 16, as well as the wire feeder. This is also true of theuse of energy—as an energy radiator, the arc plasma losses to thesurrounding environment can be 30-50 percent. Induction heating isgenerally 8 percent or less energy lost—resulting in additionalimprovement in productivity.

As used herein, the term narrow gap is intended to encompass gapscharacterized by relatively similar widths between the workpieces 32 atthe top and bottom of the workpieces 32, respectively. For example, incertain embodiments, the width between the workpieces 32 at the top ofthe workpieces 32 may only be approximately 10-75% larger than the widthbetween the workpieces 32 at the bottom of the workpieces 32, which maylead to a relatively low angle of the narrow gap of approximately10°-approximately 25°, approximately 1°-approximately 10°, approximately0°-approximately 5°, approximately 0°-approximately 2.5°, or even lower.Indeed, in certain embodiments, the width between the workpieces 32 atthe top of the workpieces 32 may be substantially similar (e.g., within0-5%) to the width between the workpieces 32 at the bottom of theworkpieces 32, which may lead to an angle of the narrow gap ofapproximately 0° (e.g., less than approximately 1°, less thanapproximately 0.5°, and so forth). It will be appreciated that other,less narrow, angles (e.g., approximately 35°-approximately 45°) may alsobenefit from the embodiments described herein.

Because of various constraints on the welding arc available energylevel, weld joints, particularly in joining thicker metal, are cut,ground, or machined to have a profile larger at the surface closest tothe welding arc. Industry statistics show that more time, perhaps asmuch as double, is needed to set-up a cutting machine to produce such abeveled weld joint profile or a V-joint profile. FIG. 16 illustrates aconventional welding operation in which a V-joint profile is used, withthe consequent loss of energy 156 from the welding arc 50. Even moretime and cost is spent creating other types of weld joint profiles, suchas J-grooves or U-grooves, with similar consequent energy loss.

FIG. 17 illustrates a welding process (a GMAW welding process, forexample) in which a generally straight narrow gap 158 is providedbetween workpieces 32 to be joined. In particular, in the illustratedembodiment, the inner (e.g., mutually facing) surfaces 159 of the narrowgap 158 may be substantially parallel to each other (e.g., within 5°,within 2°, within 1°, or even less). An induction heating coil 36 isutilized to heat the workpieces 32. The heat profile of the welding arc50 is generally balanced with the induction heat profile to provide amore balanced heating profile in the narrow gap 158. More specifically,as illustrated in FIG. 17, due to the positioning of induction heatingcoil 36 and the welding torch 16 with respect to the workpieces 32(which, again, may be actively controlled by the control circuitrydescribed herein), the combination of the induction heating profilegenerated by the induction heating coil 36 and the welding arc heatingprofile generated by the welding torch 16 may be balanced (e.g.,substantially evenly distributed) throughout the entire thicknessW_(narrow) of the straight narrow gap 158 formed between the workpieces32. For example, in certain embodiments, the heat generated on the innersurfaces 159 of the workpieces 32 may vary by less than 15%, less than10%, less than 5%, less than 2%, and so forth, along the inner surfaces159. Welds have been produced with the hybrid induction weldingprocesses described herein of zero width square butt weld joint gap. Theprocess has been shown to make acceptable welds with a gap 158 as largeas 0.125″. It appears feasible to produce welds with gaps 158 as largeas 0.375″ or larger, however, the primary benefit in productivity isgained from as narrow of a gap 158 as possible (e.g., less thanapproximately 0.375″, less than approximately 0.125″, and so forth).

It will be appreciated that the balancing between the heat profilegenerated by the welding arc 50 and the induction heat profile generatedby the induction heating coil 36 may be actively controlled by thecontrol circuitry 54 of the welding power supply 12, the controlcircuitry 62 of the induction power supply 38, or some other controlcircuitry of the system 10. For example, the control circuitry 54 of thewelding power supply 12, the control circuitry 62 of the induction powersupply 38, or some other control circuitry of the system 10, may receivesignals relating to detected operational parameters of the hybridinduction heating/welding assembly 90 from the various sensors and/orsensor modules described herein, and may determine (e.g., estimate) theheat profile generated by the welding arc 50 and/or the induction heatprofile generated by the induction heating coil 36, then determine acombined heat profile (e.g., a combination of the estimated heat profilegenerated by the welding arc 50 and the estimated induction heat profilegenerated by the induction heating coil 36), and adjust certainoperational parameters to balance the heat profile generated by thewelding arc 50 and the induction heat profile generated by the inductionheating coil 36 to, for example, minimize distortion and stresses in theworkpieces 32. For example, in certain embodiments, the positioning ofthe welding torch and/or the induction heating coil(s) 36 relative tothe workpieces 32 may be continually adjusted, for example, by the oneor more robotic manipulators 88 or other mechanical motion systemsdescribed herein (see, e.g., FIG. 2) based at least in part onalgorithms executed by the control circuitry 54 of the welding powersupply 12, the control circuitry 62 of the induction power supply 38, orsome other control circuitry of the system 10, to determine (e.g.,estimate) the heat profile generated by the welding arc 50 and/or theinduction heat profile generated by the induction heating coil 36 basedat least in part on the feedback from the various sensors and/or sensormodules of the hybrid induction heating/welding assembly 90, and thendetermine the combined heat profile (e.g., a combination of theestimated heat profile generated by the welding arc 50 and the estimatedinduction heat profile generated by the induction heating coil 36).

Side wall fusion defects are common in narrow gap welding withconventional arc welding processes. Defect repairs are costly inmaterials and labor as well as causing production scheduling delays and,thus, are a significant detriment to productivity. Because of thebalanced heating generated by the combination of an independentlycontrolled induction heating coil(s) 36 and an arc plasma (e.g.,generated by the welding torch 16), sidewall fusion defects are reducedor eliminated.

Although the use of a single induction heating coil 36 may be thesimplest application of the hybrid induction welding processes describedherein, multiple induction heating coils 36 may be used to furtherincrease productivity. In particular, in certain embodiments, a singlewide induction heating coil 36 can span the weld joint gap,simultaneously heating both sides (see, e.g., FIG. 18A). Conversely, inother embodiments, dual parallel induction heating coils 36 on bothsides of the weld joint gap can be used to double the induction heatingand, with an increase in the welding arc wire feed speed and powerlevel, to double the welding speed or more than double the welding speed(see, e.g., FIG. 18B).

Multiple induction heating coils 36 can also be used in series incertain embodiments. For example, two relatively wide induction heatingcoils 36, one in front of the other ahead of the welding torch 16 alongthe weld seam may be used to double the induction power. In addition, asillustrated in FIG. 19A, in certain embodiments, multiple sets ofparallel induction heating coils 36 may be used in series to quadruplethe induction heating power. Furthermore, as illustrated in FIG. 19B, inother embodiments, other combinations of induction heating coils 36,such as two parallel induction heating coils 36 placed in series with asingle wide induction heating coil 36 further ahead in the direction ofwelding 160 (e.g., further in front of the welding torch 16) may beused.

Multiple orientations are possible including placing the inductionheating coil(s) 36 on the back side of the weld, or positioned to favorthe direction for desired penetration, or positioned as dictated byaccess limitations. The finished weld profile (cross-section) shows thatthe melted material favors the area with induction heating. Therefore,positioning of the induction heating coil(s) 36 relative to the jointadds another level of control to influence the penetration profile of afinished weld or the preferred direction of a cutting process. Forexample, in the case of joining a thicker member to a thinner member,induction heating may be used to ensure adequate penetration on thethick member without excessive heat on the thinner member. This processmay allow for joints that were too difficult in the past usingconventional processes. Further, weld penetration will favor where thematerial is already heated. Thus, by strategically placing the inductionheating, the finished weld penetration location, depth, width, or othercritical cross-section metrics may be optimized.

There are no restrictions of the type of weld shielding gases that maybe used for hybrid induction arc processes which are gas shielded. Allof the standard weld shielding gasses should be capable of providingshielding for the hybrid induction arc welding processes describedherein. The process provides an opportunity to create new gas mixturesthat enhance hybrid induction arc welding, but which may not be suitablefor conventional arc welding processes. For example, a welding gascontaining a mixture of argon and helium in higher proportions of heliumcould be used, to enhance the arc characteristics. In an ordinarywelding process with a weld joint gap that is wider at the top, gasmixtures that contain higher percentages of low-density gases will tendto separate and the low-density gas can easily escape through the widegap opening. For example, in an argon/helium mixture, the argon wouldtend to concentrate in the bottom of the weld joint and the helium atthe top of the weld joint. For conventional GMAW processes, the highestlevel of helium in a shielding gas is 75 percent, however, for thehybrid induction heating processes described herein, a shielding gaswith 75 to 95 percent helium would provide a hotter arc with excellentsidewall wetting to prevent defects from forming. Helium is moreexpensive than argon, but the very narrow weld joint gap constrains thewidth of the volume of gas needed, and the use of a lower cost leadinggas and trailing gas will constrain the shielding gas to a small volume,thereby reducing the cost and increasing the productivity as a measureof cost per unit length of weld. Other welding gas mixtures can be usedwith the hybrid induction arc welding processes described herein, whichwould generally not be used for conventional gas shielded weldingprocesses. For example, a gas mixture of approximately 17% argon (e.g.,in a range of approximately 15-20% argon) and approximately 83% helium(e.g., in a range of approximately 80-85% helium) could be used for thehybrid induction arc welding (or cutting) processes described herein.

The hybrid induction arc welding (or cutting) processes described hereinmay utilize a travel speed that is faster than regular metal fabricationprocesses. Therefore, conventional gas delivery mechanisms may not beadequate. For example, conventional processes primarily use one gas flownozzle (e.g., for delivery of the shielding gas from the gas source 22).In contrast, the system 10 described herein may require leading, main,and trailing gas nozzles. With the additional delivery locations, thegas combustion at each location may be optimized for a particularpurpose such as heat, surface tension, purging the area of nitrogen,stirring action, process dynamics, and so forth.

In a conventional gas shielded arc welding process, once the welding archas been completed, the plasma terminates into a liquid metal pool.Conversely, with the hybrid induction arc welding processes describedherein, the narrow gap 158 is completely filled with the arc 50 suchthat arc forces keep the liquid metal out of that area of the weld jointgap, essentially creating a dam which holds back a “river” of liquidmetal, as illustrated in FIG. 20. As the welding torch 16 moves alongthe joint, the liquid metal fills in behind the welding arc 50. In orderto obtain good sidewall fusion, it is important that a thin film ofliquid metal remain coating the weld joint gap sides. Consequently, ashielding gas component which, when in contact with the liquid metal,reduces the surface energy of the liquid metal pool, will tend topromote the uniform coating of the surface of the weld joint gap withliquid metal. This is because if a gap occurs in the liquid metalcoating, it will create a higher energy surface, so the liquid metalwill stretch to maintain coverage of the solid metal surface. Thetendency to minimize surface energy is a defining factor in themorphology and composition of surfaces and interfaces. In general,wetting of a surface by a liquid is promoted if the liquid surfaceenergy with the surrounding environment is lower than that of the solidmetal surface. A gas mixture containing a gas which lowers the surfaceenergy of the liquid will, thus, promote the coating of the metalsurface with liquid metal. For example, the presence of only 50 ppmsulfur in liquid iron will reduce the surface tension by approximately20%. Sulfur hexafluoride is a relatively dense gas that is nonreactiveand nontoxic, and used as a propellant for aerosol delivery of liquidproducts. Therefore, a gas mixture of approximately 17% argon (e.g., ina range of approximately 15-20% argon), approximately 82.5% helium(e.g., in a range of approximately 80-85% helium), and approximately0.5% sulfur hexafluoride (e.g., in a range of approximately 0.1-1.0%sulfur hexafluoride), for example, could be used to promote the wettingof the sides of the weld joint gap, and prevent sidewall fusion defects.

There are no restrictions of the type of welding wire that can be usedwith the hybrid induction arc welding processes described herein.However, powdered metal core wires tend to produce a welding arc 50 witha more uniform diameter, which will provide even more heat distributionfrom the arc plasma. Since the hybrid induction arc welding processesdescribed herein do not require as much energy from the arc 50 to heatthe base material (e.g., the workpiece(s) 32), the wire may be optimizedto apply more of the energy to melt the wire. For example, solid wirethat is more resistive, or a metal core wire whose outer sheath is moreresistive (by thickness or alloy) may be used such that the wire is moreeasily melted.

Welding processes that increase the heat on the wire versus the basematerial can be used to increase the melting rate. Processes such aselectrode negative (e.g., DCEN) welding, extended electrode stickout,and AC welding processes may be used to put more heat on the wire. Ingeneral, processes that would otherwise have poor penetration may now beused with the hybrid induction arc welding processes described herein.

Certain exemplary wire/gas compositions that have been shown to producehigh quality welds at maximum speeds with the hybrid induction arcwelding processes described herein include, for example: (1) using aniron alloy wire with a composition shown in Table 1 below, and using anapproximately 17% argon/approximately 83% helium gas mixture, (2) usingan iron alloy wire with the composition shown in Table 1 below, andusing an approximately 17% argon/approximately 82.5%helium/approximately 0.5% sulfur hexafluoride gas mixture, and (3) usingan iron alloy wire with the composition shown in Table 1 below, andusing an approximately 10% carbon dioxide/approximately 90% argon gasmixture.

TABLE 1 Weld Metal Analysis Carbon (C) 0.03 Manganese (Mn) 1.57 Silicon(Si) 0.69 Phosphorus (P) 0.001 Sulphur (S) 0.006

Weld distortion is caused when the heat in a weld is not uniformlydistributed. When the metal cools, it contracts, proportionately to thetemperature of the metal (see FIG. 16). For arc welding, the electricarc radiates thermal energy. The portions of the weld which are closerto the arc receive more heat than the metal on the opposite side of theweld from the arc. As the weld cools, the hotter regions shrink morethan the cooler regions. This causes non-uniform thermal stresses todevelop in the weld. Non-uniform thermal stresses cause the metal todistort from the original size of the part before the welding processoccurred. FIG. 21 illustrates the non-uniform heat profile 162 that maybe generated by a conventional welding arc, and the distortion of aworkpiece from its original shape 164 to a distorted shape 166.

The hybrid induction arc welding process described herein utilizes twoindependent heat sources (e.g., the heat profile generated by thewelding arc 50 and the induction heat profile generated by the inductionheating coil 36), to balance the heat distribution in the weld. Theresulting thermal profile, with uniform heating, provides a weld whichshrinks uniformly and does not generate non-uniform thermal stresses. Atleast one high-frequency induction coil 36 is placed near the weldingtorch 16. The induction coil 36 heats the top of the weld up to near themelting point of the workpiece(s) 32 (e.g., greater than 50% homologoustemperature). As used in the present disclosure, the “homologoustemperature” of a material refers to the ratio of the actual temperatureof the material to the melting temperature of the material, bothexpressed in absolute temperature terms (e.g., degrees Kelvin). Then,following the induction coil 36, the arc welding process is applied bythe welding torch 16 in such a way that the bottom of the weld is heated(see, e.g., FIG. 17). The resulting thermal profile is uniform heatingthrough the weld. The weld then does not develop non-uniform thermalstresses, and the weld shrinkage is uniform through the weld. Theuniform thermal stresses do not distort the weld (contrast the uniformheat profile 168 of FIG. 22 with the non-uniform heat profile 162 ofFIG. 21).

Similar heat patterns can be developed to prevent distortion fromoccurring in other weld joint designs. For example, for T-fillet jointsthe distortion mechanism is different than for butt joints. In aT-fillet joint, the arc plasma of the welds heats the surface of thediscontinuous member, but the center column of metal is still cool. Theresult is that the cool center column in the bottom member 170 remainsrelatively fixed, while the heated metal of the surfaces of the topmember 172 and the weld metal itself cools and shrinks. This causes thetop member 172 to bend toward the weld, as illustrated by arrows 174(see FIG. 23).

By heating the surface of the weld to nearly the melting point, the arcthen provides sufficient heat to heat the entire thickness of the topmember 172, thus eliminating the cool column of metal in the center ofthe bottom member 170. When the weld cools, the top member 172 is pulledtoward the bottom member 170 by the thermal contraction of the center ofthe top member 172. The shrinking weld deposit shrinks with the topmember 172 and does not apply any stress load to the bottom member 170,thus eliminating the weld distortion (see FIG. 24). As described herein,the reduction of stresses and distortion that result from the combinedheating profile of the induction heating profile generated by the one ormore induction heating coil(s) 36 and the arc welding heating profilegenerated by the welding torch 16 may be affected by a determination ofan optimum relationship of the positioning of the one or more inductionheating coil(s) 36 and/or the welding torch 16 relative to theworkpiece(s) 32 being worked on, and independent adjustment of thepositioning positioning of the one or more induction heating coil(s) 36and/or the welding torch 16 consistent with this determination. Asdescribed herein, control circuitry (e.g., the control circuitry 54, 62of the welding power supply 12 and the induction power supply 38,respectively, or some other control circuitry of the system 10) mayreceive feedback from the sensors and/or sensor modules describedherein, and may use this feedback to determine (e.g., estimate) theinduction heating profile generated by the one or more induction heatingcoil(s) 36 and the arc welding heating profile generated by the weldingtorch 16, and may combine these determined heating profiles into acombined heating profile, determine an optimum positioning of the one ormore induction heating coil(s) 36 and/or the welding torch 16 relativeto the workpiece(s) 32 being worked on to minimize the distortion and/orstresses in the workpiece(s) 32, and then implement the determinedoptimum positioning by, for example, controlling the multiple roboticmanipulators 88 or other mechanical motion systems to independentlycontrol the position, orientation, and/or movement of the one or moreinduction heating coil(s) 36 and/or the welding torch 16 relative to theworkpiece(s) 32 in accordance with the determined optimum positioningsuch that the distortion and/or stresses in the workpiece(s) 32 areminimized. For example, in certain embodiments, the determined optimumpositioning may lead to substantially no distortion and/or stresses(e.g., less than 5% distortion, less than 2% distortion, less than 1%distortion, less than 0.5% distortion, and so forth) in the workpiece(s)32. In general, the embodiments described herein lead to welds where theworkpiece(s) 32 show at least 60%, or even greater than 80%, reductionin distortion as compared to comparable welds.

Similar heating patterns can be created in other types of weld jointsuch as lap joints. There are many different configurations of coilshape that can be applied to the process depending on the weldingconditions. Example coil configurations for butt joints are shown inFIGS. 18A and 18B. Example coil configurations for T-fillet joints areshown in FIGS. 12A through 12H.

While only certain features of the present disclosure have beenillustrated and described herein, many modifications and changes willoccur to those skilled in the art. It is, therefore, to be understoodthat the appended claims are intended to cover all such modificationsand changes as fall within the true spirit of the present disclosure.The presently disclosed methods may be used in systems using any metalfabrication processes, such as welding processes such as gas arc metalarc welding (GMAW or MIG), fluxed core arc welding (FCAW), fluxed corearc welding gas shielded (FCAW-G), metal core arc welding (MCAW),submerged arc welding (SAW), shielded metal arc welding (SMAW or STICK,or MMA or MMAW), plasma, laser, stud welding, flash butt welding, plasmawelding, spot welding, seam welding, laser welding, gas tungsten arcwelding (GTAW or TIG), friction stir welding (FSW), hybrid processeswith two or more processes together, cutting processes including plasma,oxygen, hybrid cutting processes of two or more processes, formingprocesses, or similar process.

1. A hybrid induction heating/welding assembly comprising: a metalworking tool configured to perform a metal working process on at leastone workpiece, wherein the metal working process generates a metalworking heat profile in the at least one workpiece; and at least oneinduction heating coil configured to apply induction heat to the atleast one workpiece, wherein the induction heat generates an inductionheat profile in the at least one workpiece; wherein the metal workingheat profile and the induction heat profile combine to generate acombined heat profile in the at least one workpiece, wherein thecombined heat profile produces substantially no distortion in the atleast one workpiece.
 2. The hybrid induction heating/welding assembly ofclaim 1, comprising control circuitry configured to estimate the metalworking heat profile and the induction heat profile in the at least oneworkpiece, to estimate the combined heat profile based on the estimatedmetal working heat profile and induction heat profile, and to control arelative positioning of the metal working tool, the at least oneinduction heating coil, or both, to minimize the distortion in the atleast one workpiece.
 3. The hybrid induction heating/welding assembly ofclaim 2, wherein the control circuitry is configured to control therelative positioning of the metal working tool, the at least oneinduction heating coil, or both, by transmitting control signals to atleast one robotic manipulator.
 4. The hybrid induction heating/weldingassembly of claim 2, wherein the control circuitry is configured toestimate the metal working heat profile and the induction heat profilein the at least one workpiece based at least in part on feedback fromone or more sensors.
 5. The hybrid induction heating/welding assembly ofclaim 4, wherein the one or more sensors comprise one or moreposition-detecting sensors configured to detect relative positions ofthe metal working tool or the at least one induction heating coilrelative to the at least one workpiece, one or more temperature sensorsconfigured to detect temperatures proximate the at least one workpiece,or a combination thereof.
 6. The hybrid induction heating/weldingassembly of claim 1, wherein the at least one workpiece comprises twoworkpieces that form a narrow gap.
 7. The hybrid inductionheating/welding assembly of claim 1, wherein the at least one workpiececomprises two workpieces that form a T-fillet joint together.
 8. Thehybrid induction heating/welding assembly of claim 1, wherein the atleast one workpiece comprises two workpieces that form a butt jointtogether.
 9. The hybrid induction heating/welding assembly of claim 1,wherein the metal working tool comprises a welding torch.
 10. The hybridinduction heating/welding assembly of claim 1, wherein the metal workingtool comprising a plasma cutting torch.
 11. A hybrid inductionheating/welding assembly comprising: a protective outer housing; a metalworking tool configured to perform a metal working process on at leastone workpiece, wherein the metal forming tool is at least partiallyenclosed within the protective outer housing, and wherein the metalworking process generates a metal working heat profile in the at leastone workpiece; and at least one induction heating coil configured toapply induction heat to the at least one workpiece, wherein the at leastone induction heating coil is at least partially enclosed within theprotective outer housing, and wherein the induction heat generates aninduction heat profile in the at least one workpiece; wherein the metalworking heat profile and the induction heat profile combine to generatea combined heat profile in the at least one workpiece, wherein thecombined heat profile produces substantially no distortion in the atleast one workpiece.
 12. The hybrid induction heating/welding assemblyof claim 11, comprising control circuitry configured to estimate themetal working heat profile and the induction heat profile in the atleast one workpiece, to estimate the combined heat profile based on theestimated metal working heat profile and induction heat profile, and tocontrol a relative positioning of the metal working tool, the at leastone induction heating coil, or both, to minimize the distortion in theat least one workpiece.
 13. The hybrid induction heating/weldingassembly of claim 12, wherein the control circuitry is configured tocontrol the relative positioning of the metal working tool, the at leastone induction heating coil, or both, by transmitting control signals toat least one robotic manipulator.
 14. The hybrid inductionheating/welding assembly of claim 12, wherein the control circuitryestimate the metal working heat profile and the induction heat profilein the at least one workpiece based at least in part on feedback fromone or more sensors.
 15. The hybrid induction heating/welding assemblyof claim 14, wherein the one or more sensors comprise one or moreposition-detecting sensors configured to detect relative positions ofthe metal working tool or the at least one induction heating coilrelative to the at least one workpiece, one or more temperature sensorsconfigured to detect temperatures proximate the at least one workpiece,or a combination thereof.
 16. The hybrid induction heating/weldingassembly of claim 11, wherein the at least one workpiece comprises twoworkpieces that form a narrow gap.
 17. The hybrid inductionheating/welding assembly of claim 11, wherein the at least one workpiececomprises two workpieces that form a T-fillet joint together.
 18. Thehybrid induction heating/welding assembly of claim 11, wherein the atleast one workpiece comprises two workpieces that form a butt jointtogether.
 19. The hybrid induction heating/welding assembly of claim 11,wherein the metal working tool comprises a welding torch.
 20. The hybridinduction heating/welding assembly of claim 11, wherein the metalworking tool comprising a plasma cutting torch.